Monolithically integrated thin films of conducting and semiconducting materials are used for a variety of applications requiring electronic networks. In manufacturing these thin film devices, multiple layers of differing compositions are typically deposited sequentially upon a substrate by various sputtering techniques, whereby atoms or molecules are removed from a solid target and form a gas or plasma comprising excited atoms or molecules in the vicinity of a substrate surface to form a thin film. In this regard, each layer of these thin films is typically deposited by bringing one or more species of atoms or molecules in contact with another species in or on the surface of a substrate by a sputtering technique to form a coating over the entire surface of the substrate.
Conventional manufacturing techniques for these multilayered devices require the deposition of films over the entire substrate surface, one layer at time. The coating is then removed, such as by mechanically scribing the surface where the film is to be removed or by ablation with a laser. In this regard, layers are each deposited as a film covering the entire surface and then selectively removed. Thus, numerous steps are required to manufacture these monolithically integrated films. Further, where it is desired to have different layers of films covering different portions of the surface, it is difficult to avoid removing a part of the lower layers as they are exposed during the selective removal of the last-deposited layer. In this regard, it is particularly difficult to produce high-quality monolithically integrated films over large substrate areas.
One application requiring high quality monolithically integrated networks is in photovoltaic devices used in spacecraft. These networks are deposited on relatively large sheets of substrate material, and they must be of high quality to perform efficiently over extended periods of time without maintenance. In particular, they must be substantially free of impurities, and defects and nonuniformities which can lead to degradation in performance.